Incomplete List of Disallowed Inputs Affecting dompurify package, versions <3.4.12
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-DOMPURIFY-18170233
- published22 Jul 2026
- disclosed21 Jul 2026
- creditRikuxx
Introduced: 21 Jul 2026
NewCVE-2026-66010 (opens in a new tab)How to fix?
Upgrade dompurify to version 3.4.12 or higher.
Overview
dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG.
Affected versions of this package are vulnerable to Incomplete List of Disallowed Inputs in the CUSTOM_ELEMENT_HANDLING. An attacker can cause security-relevant attributes to be preserved on allowed custom elements by leveraging the bypass of the afterSanitizeElements hook, which may result in these attributes being re-injected into an HTML sink such as innerHTML and executed in a later context.
Note: This is only exploitable if the application enables CUSTOM_ELEMENT_HANDLING, relies on afterSanitizeElements as a security policy layer, and has custom elements that re-inject preserved attribute values into an HTML sink.